Seems like GM is going to a "V" arm now. Is this better?



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<TD vAlign=top align=left height=52>Interchangeable Control Arms </TD>
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Engineering has changed the design of the lower control arm used on C/K HD trucks and the HUMMER H2.

The original A-shaped arms for the C/K HD were p/n 12475475/76 and 88982348/49 for the H2. The service arms for all vehicles are now the V-shaped arms.

The V-shaped arms are direct bolt-in replacements and require no special treatment; they simply look different. The new V-shaped arms are p/n 15103878/79 for the C/K HD and 15103880/81 for the H2.

TIP: These are the production as well as service part numbers and should not be mixed. The bushing rate for the H2 arm is much firmer than that of the C/K HD.


- Thanks to Steve Love and Dan Stress
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<DIV align=center>http://service.gm.com/gmtechlink/images/issues/may04/images/3x3/fig4ss.jpg</DIV></TD>
<TD vAlign=center align=middle width="28%" height=77>
<DIV align=center>Service
V Arm</DIV></TD>
<TD vAlign=center align=middle width="18%">
<DIV align=center>C/K </DIV></TD>
<TD vAlign=center align=middle width="20%">
<DIV align=center>15103878/79</DIV></TD></TR>
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<TD vAlign=center align=middle>
<DIV align=center>Service
V Arm</DIV></TD>
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<DIV align=center>HUMMER H2 </DIV></TD>
<TD vAlign=center align=middle>
<DIV align=center>15103880/81</DIV></TD></TR>
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<DIV align=center>http://service.gm.com/gmtechlink/images/issues/may04/images/3x3/fig5ss.jpg</DIV></TD>
<TD vAlign=center align=middle height=83>
<DIV align=center>Original Service
A Arm</DIV></TD>
<TD vAlign=center align=middle>
<DIV align=center>C/K</DIV></TD>
<TD vAlign=center align=middle>
<DIV align=center>12475475/76</DIV></TD></TR>
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<TD vAlign=center align=middle>
<DIV align=center>Original Service
A Arm</DIV></TD>
<TD vAlign=center align=middle>
<DIV align=center>HUMMER H2 </DIV></TD>
<TD vAlign=center align=middle>
<DIV align=center>88982348/49</DIV></TD></TR></T></TABLE>


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Looks like the V arm is much more stout, But I would think it needs to be seeing they have removed the brace that tied the two side arms together.


I don`t know what the benefit will be, other then maybe allowing more travel on the 2 wheel drive version. I don`t see it helping on the 4 wheel drive trucks, as to much travel will break the drive axle. (Half shaft)

There was a thread about this some time back. Some of the trucks came out with one type on one side, and the other type on the other side during the change over...http://www.dieselplace.com/forum/smileys/Confused.gif


One of the members has a fiance who is an engineer for GM and worked on the design change and testing. She told him this combination of the two arm designs was okay, but no specifics on why the change.


I suspect it has to do with cost cutting by GM, the newer design is probably cheaper to build...

Interesting that the bushing rate on the H2 is stiffer. Might help with the 4WD boosted launches.http://www.dieselplace.com/forum/smileys/Big Smile.gif

The "A" arms were holding snow and freezing solid. Then on a cold morning you roll and rip up your CV boots. I think that's why they redesigned it.

Ya my truck has one of each on it. Kind of weird, but seems to be holding up fine.

The "A" arms were holding snow and freezing solid. Then on a cold morning you roll and rip up your CV boots. I think that's why they redesigned it.


Thanks!

The "A" arms were holding snow and freezing solid. Then on a cold morning you roll and rip up your CV boots. I think that's why they redesigned it.


Is this something you read? I have the same basic design lower arms with the factory boots and have plowed since new. Snow does bunch up in the arms but has not affected anything yet. I have even had it packed up to the hood, opening the hood all you could see was snow, nothing else.

Yes I heard they were changing the design a long time ago for that reason. I don't have the source anymore.

The "A" arms were holding snow and freezing solid. Then on a cold morning you roll and rip up your CV boots. I think that's why they redesigned it.


How did you get so smart? Now that you say that I can see how it would happen, hmm I do alot of "snow wheeling" do these new A-arms fit the same as the old ones? Could I replace my older ones with this new style? thanks -Jeff

From the previous posts and especially the first post you can answer that question yourself. I didn't get smart... I read.


Edited by: hoot

Ya my truck has one of each on it. Kind of weird, but seems to be holding up fine.

The first post says you should not mix them.

Ya my truck has one of each on it. Kind of weird, but seems to be holding up fine.

The first post says you should not mix them.


Maybe he should call GM and complain?...http://www.dieselplace.com/forum/smileys/Ermm.gif


Come on Hoot, you know GM well enough to know they won't do anything about that...http://www.dieselplace.com/forum/smileys/Geek.gif


While the first post says that they should not be mixed, it doesn't cover all the trucks that were built during the change over with one of each. According to the info posted on the thread when this question came up, it's okay to have them that way, one of each design.


Also, it's not clear if that's referring to mixing H2 and HD parts, which is what it looks like to me.


On the other hand, it someone had to replace on of the older style, I can see this bulleting being used to sell another part for the other side...http://www.dieselplace.com/forum/smileys/Confused.gif